BBC News reports NASA's Dawn probe has successfully entered orbit around Vesta, a 530 kilometer wide asteroid.
"Today, we celebrate an incredible exploration milestone as a spacecraft enters orbit around an object in the main asteroid belt for the first time," Nasa Administrator Charles Bolden said in a statement.
"Dawn's study of the asteroid Vesta marks a major scientific accomplishment and also points the way to the future destinations where people will travel in the coming years. President Obama has directed Nasa to send astronauts to an asteroid by 2025, and Dawn is gathering crucial data that will inform that mission."
Vesta was discovered in 1807, the fourth asteroid to be identified in the great belt of rocky debris orbiting between Mars and Jupiter.